A taxonomic study of the genus Hellenocarum H.Wolff (Umbelliferae-Apioideae)based on morphology, fruit anatomy, and molecular data

摘要

Phylogenetic relationships among the species of Hellenocarum and its close allies (Umbelliferae-Apioideae) were investigated using nuclear (ITS, ETS) and plastid (psbA-trnH intergenic spacer) DNA sequences. The results obtained were supplemented with an examination of morphology from herbarium and field-collected materials, as well as details of fruit anatomy obtained from light and scanning electron microscopy. According to the molecular data, Hellenocarum is not monophyletic. In most molecular analyses, the genus comprises 2 disparate lineages, with each lineage supported by distinct morphological characters (e.g., structure of underground organs, shape of the umbel, petal color). The first lineage includes Hellenocarum multiflorum (the type species) and H. Strictum and corresponds to Hellenocarum sensu stricto. The second lineage includes Hellenocarum amplifolium and H. Pisidicum and is recognized herein as the new genus Neomuretia Kljuykov, Degtjareva and Zakharova. Carum depressum is united with Hellenocarum sensu stricto. Three new nomenclatural combinations are proposed: Hellenocarum depressum (Hartvig and Kit Tan) Kljuykov and Zakharova; Neomuretia amplifolia (Boiss. And Hausskn.) Kljuykov, Degtjareva and Zakharova; and Neomuretia pisidica (Kit Tan) Kljuykov, Degtjareva and Zakharova.